1. Field of the Invention
The present invention relates to a method of forming a thin film capacitor having a tantalum oxide dielectric.
2. Description of the Prior Art
In the manufacture of thin film capacitors, it has heretofore been necessary to first form a thin film of tantalum as the first electrode on a dielectric substrate. This composite would then be placed in an anodizing bath to form a layer of tantalum oxide on the tantalum film, which procedure required an abnormally long period of time, thereby adding greatly to the cost of manufacturing a capacitor. Capacitors produced by such methods required the use of tantalum metal, resulting in a device having polar characteristics. Further, when in the past a definite capacitor pattern was required, complicated and time consuming photolithographic, or the like techniques were required to produce well defined edges to reduce edge effect problems.
Prior art efforts to form tantalum oxide dielectric layers on non-tantalum electrodes resulted in a significant reduction in the value of breakdown voltage with a large increase in leakage current.